import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'NoficationListener'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: NotificationListener(
        onNotification: (notification) {
          switch (notification.runtimeType) {
            case ScrollStartNotification:
              print('开始滚动');
              break;
            case ScrollUpdateNotification:
              print('正在滚动');
              break;
            case ScrollEndNotification:
              print('滚动停止');
              break;
            case OverscrollNotification:
              print('滚动到边界');
              break;
            default:
          }
        },
        child: ListView.builder(
          itemCount: 100,
          itemExtent: 50,
          itemBuilder: (context, index) {
            return ListTile(title: Text('$index'),);
          },
        ),
      ),
    );
  }
}
